Figure 3.

Clam Cdc20 sediments as part of a large complex in both mitotic and interphase cells. Extracts of interphase 1 or early mitosis 1 clam oocytes were separated on 15%–40% sucrose gradients. Gradient fractions were analyzed by Western blotting with antibodies raised against clam Cdc20 or human Cdc16 (49). Cdc16 is a component of the APC/C, and thus indicates the position of the 1,500-kDa clam oocyte APC/C (4). T is a sample of the total extract loaded on the gradient, and numbers indicate gradient fractions (top to bottom). Size markers are BSA (B; 65 kDa, 4.5 S), catalase (C; 248 kDa, 11.3 S), and thyroglobulin (Th; 670 kDa, 19 S) (4, 12, 17).